Made in USA. Sold in pairs, these Pure Stealth 10MM-1.0 Male Inverted Flare x -3AN Male adapters are made of steel and coated with our proprietary Pure Stealth black ceramic coating. Includes optional crush washers for 10MM-1.0 applications that are not inverted flare. Crush washers require a machined flat surface around port opening of approx. .100" to seal properly. Although our Pure Stealth coating is extremely durable, it can be scratched. Care should be taken during assembly to prevent damaging the coating,